A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
Airfoils used on vanes and blades in the turbine section are exposed to high temperature, high-speed exhaust gas flow. A stream of cooling airflow is therefore often provided along exposed surfaces of the airfoils because the temperature of the exhaust gas flow is generally higher than the melting temperature of the airfoil material. Cooling channels within the airfoil communicate cooling air to openings to generate the desired cooling airflow.
Airfoils are typically molded parts and the internal cavities and passages required to communicate cooling airflow are provided by core assemblies over-molded during a molding process. Therefore, there is a need to efficiently cool airfoils exposed to the high temperature, high-speed exhaust gas flow.